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Evaluation of a function

Compute f(a): that is, calculate the value of a function f(x) or an expression at a given point a and display the calculation steps.
Function variable (one letter)
To multiply, use a*b not ab

This handy tool allows you to calculate the value of a function for a given value of its variable. For example, if you have a function `f(x)`, and you want to know the value of `f` when `x = 5`, our calculator will provide you with the answer.

Form Usage Guide

To use the calculator, follow these simple steps:

  1. Variable: Enter the main variable of your function. For example, for `f(x)`, enter `x`.
  2. Function: Enter your function. For example, x^2 + x + 1.
  3. Variable Value: Enter the value for which you want to calculate the function. For example, `5`.

Examples and Practical Cases

Here are some examples to help you better understand how to use the calculator:

  • For the function `f(x) = x^2`, and the value `x = 4`, the output will be `16`.
  • With `f(x) = 2*x + 3` and `x = 5`, the result will be `13`.
  • If you have `f(x) = sin(x)` and `x = pi/2`, the calculator will display `1`.

Common Errors and Their Corrections

Be aware of these common errors:

  • Forgetting * for multiplication. For example, "ax" should be written as "a*x".
  • Forgetting parentheses in complex expressions, like `sin(x + pi/2)` instead of `sin x + pi/2`.

Table of Functions and Operators

Variables A function can have one or more variables, but only one main variable.
A variable is a single lowercase or uppercase letter.
Examples:
A function f with one main variable : f(x) = 4*x
A function g with one main variable x and a secondary parameter m,
g(x) = 4*x*m + x + 1,
In this case, enter x in the “main variable” field
Numbers Use a dot as decimal separator
Operators + (addition),
- (substration),
* (multiplication),
/ (division),
^ (power),
For multiply operator, enter a*b not a.b nor ab. Example: 2*x.
Constants You may use these constants :
pi (approx. 3.14),
e (approx. 2,72)
Examples: f(x) = pi * x or f(x) = e * (x+1+2*e)2
Common Functions You may use theses functions in the expression of f(x)
sqrt(x) (square root),
exp(x) (exponential function),
log(x) or ln (natural logarithm),
Trigonometric functions You may use theses functions in the expression of f(x)
sin (sine),
cos (cosine),
tan (tangent),
cot (cotangent),
sec (secant),
csc (cosecant),
Inverse trigonometric functions You may use theses functions in the expression of f(x)
arcsin (arcsine),
arccos (arccosine),
arctan (arctangent),
arccot (arcotangent),
arcsec (arcsecant),
arccsc (arccosecant),
Hyperbolic Functions You may use theses functions in the expression of f(x)
sinh (hyperbolic sine),
cosh (hyperbolic cosine),
tanh (hyperbolic tangent),
coth (hyperbolic cotangent),
sech (hyperbolic secante),
csch (hyperbolic cosecant)
Inverse hyperbolic functions You may use theses functions in the expression of f(x)
asinh (inverse hyperbolic sine),
acosh (inverse hyperbolic cosine),
atanh (inverse hyperbolic tangent),
acoth (inverse hyperbolic cotangent),
asech (inverse hyperbolic secant),
acsch (inverse hyperbolic cosecant)

See also

Derivative of a function
Primitive of a function
Taylor series expansion
Function limit
Definite Integral